Therapeutic Evaluation of Nyctanthes Arbor-Tristis on Obsessive Compulsive Disorder

Nyctanthes arbor-tristis (NAT), also known as Parijata or Harsinghar is an Indian traditional plant of great importance. It has been used in Ayurveda, Siddha and Unani system of medicine for treatment of various infectious and non-infectious diseases. Each part of the plant has some medicinal value and is used for various pharmacological actions.[1] Nyctanthes arbor-tristis has been used for centuries in Ayurvedic medicine, either alone or in combination with other herbs, as a memory and learning enhancer, sedative, anti-epileptic, antidepressant and antianxiety.[2] Animal studies of Nyctanthes arbor-tristis whole plant or alcohol extracts have reported cognition enhancing effects including improved motor learning and acquisition, consolidation, and retention of memory.[3] which suggests that Nyctanthes arbor-tristis influences various neurotransmitter systems including serotonergic system.[4] Obsessive–compulsive disorder (OCD) is characterized by persistent ritualistic thoughts (obsession) which are ego-diatomic and associated with seemingly purposeful behaviors (compulsions). [5] Its co-morbidity with major depression is often evident, and it is considered as an anxiety disorder.[6] Potent serotonin reuptake inhibitors (SSRIs) are consistently effective in patients of obsessive- compulsive disorder which indicates that serotonin dysfunction is the underlying cause in OCD.[7] An outgrowing research has been done in pharmacotherapy of OCD but research into effective herbal treatments for OCD has just started. Those plants which are used to treat anxiety and depression can be a potential therapeutic strategy for treatment of OCD. [8] Evidences shows that Nyctanthes arbor-tristis may be useful in the treatment of obsessive-compulsive disorder. Therefore, the influence of ethanolic extract of Nyctanthes arbor-tristis was investigated on the marble-burying behavior of mice a well-accepted model of obsessive-compulsive behavior, due to its high face and predictive validity. [9]

MATERIALS AND METHODS

Collection and identification of plant materials:

The plant of Nyctanthes arbor-tristis collected was from the medicinal garden of Vidyabharati college of pharmacy. Identified and authenticated by Prof. Kajal Apale Department of Botany, Vidyabharati Mahavidyalaya, Amravati.

The flowers of Preparation of plant extract:

Nyctanthes arbor-tristis was collected from healthy plants, cleaned properly, and dried at shade at room temperature. The dried plant materials were finely powdered and macerated thrice with 80% (v/v) ethanol in shaking condition for 7 days at room temperature. The extract thus obtained were filtered and concentrated by air drying and stored at 4°C.

Drugs and administrations:

Fluoxetine hydrochloride was purchased from local market of Amravati, India. Ethanolic extract of Nyctanthes arbor-tristis (EENAT) and Fluoxetine HCl were prepared in 0.9% saline. Fluoxetine HCl was administered orally. EENAT and saline were administered orally. All drug solutions were prepared fresh.

Selection of animal:

The Male Swiss albino mice (weighing 20-25g), were obtained from the animal house of department of Pharmacology, Vidyabharati college of Pharmacy, Amravati. All the animals were acclimatized to the animal house prior to use. They were kept in cages in animal house with a 12hr light: 12hr dark cycle at temperature (25±1°C) with 50±55% of relative humidity. Animals were fed on pellets and tap water ad libitum. The care and handling of mice were in accordance with the internationally accepted standard guideline for use of animals (CPCSEA). Experiments were performed in accordance with the committee for the purpose of control and supervision of experimental animals (CPCSEA) guidelines after the approval of the experimental protocol by the Institutional animals ethical committee (IAEC).

Phytochemical screening:

The crude extracts of Nyctanthes arbor-tristis were subjected to preliminary phytochemical screening for their presence and absence of active phytoconstituents. [10]

Experimental design:

Mice were divided into different groups (n=6). EENAT (200, 400 mg/kg) p.o. fluoxetine(15 mg/kg). EENAT and fluoxetine were administered orally (p.o.) 30 min prior to the assessment of marble-burying behavior and locomotor activity. The control group received 0.9% saline (10 mL/kg, po). After 30 min, the marble-burying behavior and motor activity were assessed in separate groups.

Evaluation of Anti obsessive-compulsive activity:

Marble Burying Behavior

The marble burying test takes advantage of the mice’s natural proclivity for digging in the natural settings (e.g., burrows and escape tunnels) and in standard cage bedding. Briefly, male mice were placed in a polypropylene cage (37 cm × 21cm x 14 cm) with 20 glass marbles (10 mm in diameter) that were evenly dispersed on 5 cm deep sawdust for 20min without access to food or drink. The testing cages were kept in a separate room from the housing area. The number of marbles buried at least 2/3 of the way within 20min was used to measure compulsive-like digging behavior recorded.[11]

Motor Activity By Actophotometer

The locomotor activity was measured using an actophotometer.The movement of the animal cuts off a beam light falling on the photocell and a count was recorded and displayed digitally. Motor activity was assessed in terms of total number of counts of light beam inter-ruptions in 10 min. An acquisition period of 5 min was given to each mouse before assessment of motor activity. [12]

Statisical Analysis:

The data were expressed as a mean ± SEM. Results were analyzed statistically by one way ANOVA followed by Dunnet test. Statistical significant was considered as P< 0.05 in all cases.

RESULTS

Preliminary Phytochemical Screening Phytochemical test of Nyctanthes arbor-tristis revealed the presence of Alkaloids, Flavonoids, Glycoside, Sterols, Terpenoids, Phenol, Tannin.

Table no.1: Phytochemical investigation of Nyctanthes arbor-tristis

Effect of EENAT on marble burying behavior and motor activity:

One way ANOVA exhibited that EENAT significantly influenced marble burying behavior. The Dunnets test showed that the EENAT, 200 and 400 mg/kg significantly reduced the number of marbles buried (Table no.2 and fig no. 1) Motor activity was not affected by EENAT at the dose of 200 and 400 mg/kg, however EENAT at a dose of 400mg/kg significantly suppressed the locomotor activity (Table no.3 and fig no. 2).

Marble burying behavior

Table no.2: Effect of ethanolic extract of Nyctanthes arbor-tristis on marble burying behavior in mice.

Each value represents the mean ± S.E.M (n=6). (*p<0.0001) compared with control and standard group.

Effect of ethanolic extract of Nyctanthes arbor-tristis on marble burying behavior in mice.

Each value represents the mean ± S.E.M (n=6). (*p<0.0001) compared with control and standard group.

Figure 1. Effect of ethanolic extract of Nyctanthes arbor-tristis on marble burying behavior in mice.

Motor activity:

Table no.3: Effect of ethanolic extract of Nyctanthes arbor-tristis on motor activity in mice.

Each value represents the mean ± S.E.M (n=6). (*p<0.0001) compared with control and standard group.